12 lines
No EOL
417 B
HLSL
12 lines
No EOL
417 B
HLSL
#include "../../math/const.hlsl"
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#ifndef FNC_CHARLIE
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#define FNC_CHARLIE
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float charlie(float NoH, float roughness) {
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// Estevez and Kulla 2017, "Production Friendly Microfacet Sheen BRDF"
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float invAlpha = 1.0 / roughness;
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float cos2h = NoH * NoH;
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float sin2h = max(1.0 - cos2h, 0.0078125); // 2^(-14/2), so sin2h^2 > 0 in fp16
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return (2.0 + invAlpha) * pow(sin2h, invAlpha * 0.5) / TAU;
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}
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#endif |